Microcyclops finitimus Dussart, 1984

Perbiche-Neves, Gilmar, Corgosinho, Paulo H. C., Previattelli, Daniel, Suárez-Morales, Eduardo, Nogueira, Marcos G. & da Rocha, and Carlos E. F., 2025, Catalogue for identification of the most common lacustrine and riverine cyclopoid copepod (Crustacea) species in plankton of La Plata Basin, South America, Zoologia (e 24023) 42, pp. 1-47 : 32

Microcyclops finitimus Dussart, 1984

Figs 32, 33

Diagnosis. Adult female, 580 µm in length excluding caudal setae ( Figs 32A, 33A ). Prosomites 4 and 5 with a finely serrulate membrane on the distal margin and at the corners ( Fig. 33B, C ), dorsal margin of first to third prosomites smooth. Last P1-endopod segment has a pore on the anterior surface, close to the outer margin, also a row of small spinules on the distal margin; terminal spine 1.2 times longer than the segment ( Fig. 32B ). Caudal ramus 4 times longer than wide ( Fig. 33D ).

Remarks. The illustrated specimen was collected in the Tietê River, in the Três Irmãos reservoir. It has a wide distribution in South America, from Venezuela to the upper Paraná River Basin. It is more common near macrophyte banks or in the littoral zone. In the sampling sites it was relatively frequent, along with M. anceps . A complementary description of this species was provided by Gutiérrez-Aguirre and Cervantes-MartÍnez (2016).

Figures

Figures 32–33. Microcyclops finitimus, female. 32: (A) dorsal view of adult female, with detail of the serrated membrane of the distal margin of prosomites 4 and 5 (see also Figure 33B); (B) P1–endopod, pore and ornamentation of terminal spine, indicated by arrows. 33: (A) habitus, dorsal; (B); (C) distal margin of last prosomite and genital double-somite with finely serrulate membranes; (D) caudal rami, dorsal view. Scale bars: Fig. 32: A = 200 µm, B = 50 µm, Fig. 33: A = 500 µm, B, C = 50 µm; D = 100 µm.